The specific recognition of tumor antigens by CD8+ T cells, and the binding of monoclonal antibodies to tumor targets represent the main effector mechanisms for immune-mediated tumor rejection. The exquisite specificity of these interactions has earned cancer immunotherapy the designation as a targeted therapy. Excitement in this area was reinforced by the FDA approval of several monoclonal antibodies, such as Herceptin for breast cancer and Rituxan for lymphoma, as well as two cytokines, interleukin-2 and interferon-a, for the treatment of melanoma and kidney cancer. In addition, allogeneic bone marrow transplantation has therapeutic effects through a cell-mediated graft-versus-tumor immune response. However, the efficacy of these therapies is still suboptimal. Improving upon the effectiveness of current agents, developing new immunotherapeutic interventions (such as anti-cancer vaccines), and elucidating the mechanism of success versus failure of investigational treatments, all require careful monitoring of scientific endpoints. The main purpose of the Human Immunologic Monitoring Facility is to perform such assays in the context of clinical trials in cancer patients. As such, it serves as a specialized laboratory for evaluating pharmacodynamic parameters in response to agents or interventions that impact on immune cells. This service enables a range of clinical cancer researchers, who don't necessarily have laboratory expertise themselves, to measure immunologic endpoints in participating study subjects. The Facility also monitors biologic effects of other pharmacologic agents (such as signal transduction inhibitors) using lymphocytes or other hematopoietic cells as a surrogate tissue. Finally, the technologists of our Core interface with the cGMP Facility to carry out the preparation of clinical-grade products, such as cancer vaccines, for administration to patients. Thus, this Facility lies at the heart of our clinical/translational effort in cancer immunotherapy, and is vital for the scientific investigation of additional novel agents.